Serpent's Wall
Ukraine
The Serpent's Wall (Ukrainian: Змієві вали, romanized: Zmiievi valy, lit. 'Winged dragon's walls') is an ancient system of earthworks (valla) located in the middle Dnieper Ukraine (Naddniprianshchyna) that stretch across primarily Kyiv Oblast, Ukraine. They seem to be similar in purpose and character to Trajan's Wall situated to the southwest in Bessarabia. The remaining ancient walls have a total length of 1,000 km and constitute less than 20% of the original wall system.
Archaeological site data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).